Release 8.0.4 fixes (#256)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>
Co-authored-by: Laughing <61612323+Laughing-q@users.noreply.github.com>
Co-authored-by: TechieG <35962141+gokulnath30@users.noreply.github.com>
Co-authored-by: Parthiban Marimuthu <66585214+partheee@users.noreply.github.com>

ultralytics/yolo/v8/detect/train.py

@@ -199,6 +199,7 @@ class Loss:
 def train(cfg):
     cfg.model = cfg.model or "yolov8n.yaml"
     cfg.data = cfg.data or "coco128.yaml"  # or yolo.ClassificationDataset("mnist")
+    cfg.device = cfg.device if cfg.device is not None else ''
     # trainer = DetectionTrainer(cfg)
     # trainer.train()
     from ultralytics import YOLO